Silver
Definition and meaning of Silver in chemistry.
Silver is a soft, white, and highly lustrous metal designated by the chemical symbol Ag and an atomic number of 47. It is globally renowned for possessing the highest electrical conductivity, thermal conductivity, and optical reflectivity of any known metal. The elemental symbol Ag is derived from the Latin word argentum, reflecting its ancient historical significance as a precious coinage metal.
In more detail
Positioned in group 11 of the periodic table alongside copper and gold, silver is a ductile transition metal found in the Earth's crust both in its pure elemental form and combined in minerals like argentite and chlorargyrite. Its remarkable electrical and thermal properties stem from a single s-orbital electron in its outermost shell that moves freely and efficiently within the metallic lattice structure. Silver is highly resistant to general corrosion in clean air and water, ensuring long-lasting durability in various physical environments. However, it noticeably tarnishes upon prolonged exposure to airborne ozone or ambient hydrogen sulfide gas, forming a characteristic dark surface layer of silver sulfide (Ag2S). The metal readily forms diverse chemical compounds in the +1 oxidation state, with silver nitrate (AgNO3) serving as a versatile precursor to synthesize many other silver-based materials. Furthermore, silver halides are famously photosensitive, a unique chemical property that historically formed the fundamental foundation of traditional photographic film and radiographic imaging.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Ag |
| Atomic number | 47 |
| Atomic mass | 107.87 u |
| Category | Transition Metal |
| State at room temperature | Solid |
| Melting point | 961.78 °C |
| Boiling point | 2162 °C |
| Year discovered | Ancient |
Because of its unparalleled electrical conductivity, silver is extensively used in high-quality electronic contacts, sensitive mechanical switches, and radio-frequency connectors.
Frequently asked questions
Why does silver tarnish over time?
Silver tarnishes because it reacts with trace amounts of hydrogen sulfide gas in the air, creating a dark, dull coating of silver sulfide on its surface.
Is silver the best natural conductor of electricity?
Yes, silver has the highest electrical conductivity of all elemental metals, surpassing even highly conductive metals like copper and gold.